I went through @compudanzas uxn tutorials once, had fun, and forget everything again. So I did it again, but this time I tried to make some literate programming style notes about all the different aspects I'm picking up. I'm through with my second attempt and I have to say that it was worth the effort. At least the basics stuck now (or so he hoped...)
The notes can be found here but I haven't cleaned up anything yet. I'm pretty sure I have some conceptual mistakes in there as well. The format is also not very consistent along the notes, since I lost patience with myself at times.